On this day in 1985, Western Mexico and parts of Mexico City woke to an 8.1-magnitude earthquake that caused between $3-$4 billion in damage and a death toll cited as 10,000 people but could be as high as 40,000.
Initially, the Mexican government refused foreign aid, but after an aftershock on September 20, the government allowed help to pour in.
You can read about the earthquake and foreign aid from the perspective of U.S. FSOs working in Mexico City at the time by following the link.